Body compressed, with narrow caudal peduncle. Medium-sized mouth, ending under anterior part of eye. Teeth in lower jaw knife-like; small and gently curved in the upper jaw. Two dorsal fins, the first originated above the operculum vertically in front of pectoral fin origin. Caudal fin forked. Very small scales, covering dorsal and anal fins bases. Tubes scales of lateral line close to dorsal profile.
dark blueish to grey-brownish and purple. Upper margin of dorsal fins and lower margin of anal fin dark.
common 12-16 cm (max. Mediterranean 60 cm, elsewhere 80 cm).
Tetrapterus spp.: body cylindrical and elongated, first dorsal fin origin behind vertical of pectoral fin origin.
Centrolophus spp. and Schedophilus spp.: a single dorsal fin.
Cubiceps spp.: 20-26 soft rays in the second dorsal fin.
BIOLOGY / ECOLOGY
Feeds on zooplankton and small mesopelagic fishes.
juveniles epipelagic or mesopelagic, often under floating objects. Adults demersal on the continental slope.